Iran's parliament speaker said Sunday that an attack that killed 27 members of Iran's elite Revolutionary Guard was "planned and carried out from inside Pakistan," which he said should answer for it.

Ali Larijani's remarks, carried by the state-run IRNA news agency, came after Iranian officials initially accused Saudi Arabia and the United Arab Emirates of being behind the attack. The Gulf Arab states are deeply suspicious of Tehran and at war with Iran-aligned rebels in Yemen.

Pakistan is closely allied with Saudi Arabia, but has tried to maintain a balancing act between Riyadh and Tehran. Saudi Arabia's Crown Prince Mohammed bin Salman is expected to visit Pakistan Sunday after delaying his arrival by one day without providing an explanation.